Is There a Relationship Between Hypercholesterolaemia and Noise-induced Hearing Loss?

Abstract

Many investigators who have analysed the possible correlation between hearing loss and high serum cholesterol levels have found that hearing appears to be influenced by high blood lipids. Noise, as is well known, also influences hearing, particularly at high frequencies. It increases serum cholesterol levels during short-term experiments. The present investigation addresses the question of a possibly increased ototraumatic influence by the combination of high serum cholesterol levels and occupational noise exposure. Seventy-eight 50-year-old men with high serum cholesterol levels from a WHO study were compared with 75 50-year-old men who were randomly selected from the same WHO material. Group mean audiograms showed that hearing was similar in both groups, with a moderate high frequency hearing loss having a configuration suggestive of a noise-induced hearing loss. Analysis of the individual histories and the pure-tone audiograms showed that noise was the most predominant factor influencing hearing at any specific frequency or combination of frequencies. There was a statistically significant tendency for the high-cholesterol group that had suffered the most noise exposure, to have a high-frequency hearing loss. There was also a tendency for the low-cholesterol group to have a high-frequency loss if they had been excessively exposed to occupational noise. No further correlations were found. The present results indicate a slightly increased risk of acquiring a high-frequency sensorineural hearing loss for people who work in noisy environments and have high serum cholesterol levels.

Dyslipidemia and Auditory Function

“…They conducted several epidemiologic studies in different areas of the world and suggested that diet is an important factor for prevention of coronary artery disease and hearing loss (10). There have also been several other studies conducted that suggest a relationship between hyperlipidemia and hearing loss, especially presbycusis and noise-induced hearing loss (11,12). Others describe a relationship between specific lipid fractions and hearing disturbances (13,14).…”

QTL Mapping of Endocochlear Potential Differences between C57BL/6J and BALB/cJ mice

“…Spearman rank analysis for mean EP after noise revealed 37 significant correlations for widely divergent traits, yet cholesterol and thyroxin again comprised two of the top three. Both cholesterol and thyroxine regulation have been implicated in cochlear function and susceptibility to injury (Kohonen et al 1971;Berndt and Wagner 1979;Axelsson and Lindgren 1985;Crumling et al 2012). It is thus possible that some common genes or downstream cascades involving these partly mediate noise-related EP changes.…”

Heparin Induced Extracorporeal LDL Precipitation (H.E.L.P.) in Treatment of Tinnitus: A Randomised, Multicentre Trial

“…High serum LDL and low HDL are commonly accepted as major vascular risk factors. Many authors assume that hyperlipidemia with the subsequent hyperviscosity of the blood and atherosclerosis reduce the cochlear perfusion and thus may trigger disorders in hearing function [9,16,17]. Indeed, histochemical studies on the inner ear of hypercholesterolemic animals showed a vacuolar degeneration of the capillary vessels of the stria vascularis [18] and elctro-licent patches of an amorphous material in strial marginal cells throughout the cochlea and in OHC [19].…”

“…However, until today little is known about the underlying pathomechanisms. Experimental and clinical data suggest that elevated serum cholesterol and fibrinogen might be cofactors in the development of hearing disorders [3,4,7,[9][10][11]. Fibrinogen/LDL apheresis is an established procedure to acutely reduce the concentration of serum LDL and lipoprotein (a) to 60% and that of fibrinogen to 65% of the original values.…”